Problem: Simplify the following expression: $k = \dfrac{12y - 4x}{2x - 8} + \dfrac{4z}{2x - 8}$ You can assume $x,y,z \neq 0$.
Explanation: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{12y - 4x + 4z}{2x - 8}$ The numerator and denominator have a common factor of $2$, so we can simplify $k = \dfrac{6y - 2x + 2z}{x - 4}$